Judicial Discretion and Civil Procedure: the Effect of Ideology on Rule 12(b)(6) Motions After Twombly and Iqbal

Abstract: This paper argues that judicial ideology pervades civil procedure. When ideological judges have procedural discretion, they act in ways that are statistically predictable. We show this using two recent decisions by the Supreme Court, Bell Atlantic Corp. v. Twombly and Ashcroft v. Iqbal. These decisions substantially increased the discretion judges had to summarily dismiss cases. We compare summary dismissal behavior of federal district court judges in pre- Twombly / Iqbal environmental cases to post-Twombly / Iqbal environmental cases. We show that before these cases, Democratic-appointed and Republican-appointed judges dismissed cases brought by pro-environment plaintiffs with no statistically different behavior. However, after these two cases, Republicans-appointed judges were much more likely to summarily dismiss environmental cases than Democratic-appointed judges. We believe this is likely only the tip of iceberg in understanding how judicial ideology and political partisanship may pervade civil procedure.